Bushing joint

ABSTRACT

A sleeve joint with a mount assembly unit ( 1 ) and with an inner part ( 2 ) is presented, in which the mount assembly unit ( 1 ) has a housing ( 3 ) as well as a bearing shell ( 4 ) inserted into the housing ( 3 ) for the slidingly movable mounting of a mount body ( 6 ) provided with a curved support surface ( 5 ). The mount body ( 6 ) is provided with a sliding layer ( 8 ) on its inner surface ( 7 ) facing away from the curved support surface. A sliding movement of the mount assembly unit ( 1 ) is made possible in the longitudinal direction of the sleeve joint as a consequence of the sliding contact between the mount assembly unit ( 1 ) and the inner part ( 2 ) associated with same.

FIELD AND BACKGROUND OF THE INVENTION

The present invention pertains to a sleeve joint as can be used mainlyfor connecting the stabilizer in motor vehicles. The rubber mounts usedin this area so far tend to be worn prematurely as a consequence of theheavy burden of contaminants and corrosive media near the wheels.Moreover, the problem arises that during the springy movements of thewheel, the stabilizer has an excessive radial pretension, whichoverloads it in an undesired manner. In particular, a bending moment isundesirable for the stabilizer bar, because it impairs the responsecharacteristic of the stabilizer bar during its normal operation in themotor vehicle. Stabilizers are regularly suitable and designed only forabsorbing torsional stresses. Besides the risk of damage to thestabilizer, the rubber mount accommodating the stabilizer bar is,moreover, also squeezed, which may lead to the destruction of the innermolecular structure of such elastomer mounts, so that they will failprematurely. The rubber mounts or sleeve joints used hitherto oftenhave, moreover, the drawback of generating squeaky noises during themovement of the stabilizer, and the response characteristic andconsequently the efficiency of the stabilizer are, moreover, alsoinsufficient because of strong frictional effects.

SUMMARY OF THE INVENTION

The basic technical object of the present invention is to provide asleeve joint that has low friction and can compensate both tiltingmovements and longitudinal movements of the component to be mounted.

According to the invention, a sleeve joint is provided with a mountassembly unit as well as an inner part. The mount assembly unit iscomposed of a housing as well as a bearing shell inserted into thehousing for the slidingly movable mounting of a mount body provided witha curved support surface. The mount body is provided with a slidinglayer on its inner surface facing away from the curved support surface.As a consequence of the sliding contact between the mount assembly unitand the inner part associated therewith, a sliding movement of the mountassembly unit is consequently possible in the longitudinal direction ofthe sleeve joint.

Such a sleeve joint according to the present invention has the advantagethat an additional axial sliding mount was created here in addition tothe known joint designs. Due to the separation of the bearing shell andthe sliding layer, the selection of the material for these componentscan be optimized and correspondingly adapted to the special requirementsimposed on them. It is thus possible to compensate the harmful effectsof forces, which hitherto acted on the bearing as well as on thecomponent to be mounted, by an axial movement. The axial mobility of thesleeve joint according to the present invention prevents, moreover, theintroduction of bending forces into the component to be mounted. If thisis a stabilizer for a motor vehicle, the response characteristic of thestabilizer as a whole is improved hereby.

For example, a stabilizer can be mounted in a motor vehicle very closeto the wheel when a sleeve joint according to the present invention isused as a consequence of the compact design of the sleeve joint, sothat, on the one hand, an increase in the efficiency of the stabilizercan be observed, and, on the other hand, the hitherto necessary rockerpendulums can be eliminated. The sleeve joint according to the presentinvention has, moreover, a simple design and can therefore bemanufactured economically and at a low cost.

According to another embodiment of the present invention, it is proposedthat the sleeve joint, sealed toward the outside, be designed withgrease lubrication on the slidingly movable mount parts. Due to thegrease lubrication and the selection of a suitable material for thegrease to be used, the service life of a sleeve joint according to thepresent invention can be advantageously prolonged, on the one hand, andthe squeaky noise, which has hitherto been felt as being disturbing insleeve joints in extreme load situations, can be avoided, on the otherhand. It would even be possible theoretically to use two different typesof grease for the sliding mounting between the bearing shell and themount body as well as for the sliding mounting between the inner partand the sliding layer, which may be definitely meaningful depending onthe material pairing selected.

To prevent the penetration of contaminants and corrosive media such asoils or alkaline solutions or salt-containing liquids into the interiorof the mount, the solution according to the present invention isimproved such that it preferably has two sealing bellows, whose firstedge area is inserted into a housing mount and whose second edge area isbrought sealingly into contact with the inner part. Hermetic screeningof the inner components of the sleeve joint against the environment isthus possible in a simple manner.

According to one embodiment of this idea, a groove in the outer surfaceof the housing or a closing ring, which is connected to the housing andreceives the edge area of the sealing bellows, may be used as thehousing mount. The closing ring may be connected to the housing in theknown manner by deforming a housing edge, which is possible, e.g., bymeans of a rolling operation. However, to guarantee the dual function ofthe closing ring, the latter may also be used at the same time to fixthe bearing shell within the housing and to optionally pretension same.The moments of friction within the mount assembly unit can be influencedspecifically in a favorable manner due to this measure. Moreover, it is,of course, possible to fix the sealing bellows on the componentsassociated with them by means of straining rings to achieve animprovement of their sealing.

In keeping with the object of the present invention, namely, to improvethe friction within the sleeve joint as a whole, it is, moreover,proposed that the sliding layer be prepared from a low-friction plasticor a synthetic or rubber. The necessary coefficients of friction of thesliding pairing shall be taken into account here in selecting thematerial for the sliding layer. At any rate, it is meaningful accordingto the present invention for the material of the sliding layer to be aninjection-moldable plastic rubber. This facilitates the processing ofthe material, so that it can also be injected, e.g., directly onto themount body. As a result, the number of consecutive operations involvedin the manufacture can be considerably reduced. However, it is alsopossible to prepare the sliding layer and the mount body separately fromone another in order to subsequently connect them to one another bymeans of a press fit.

A sleeve joint according to the present invention has a decisiveadvantage over prior-art designs also because a grease-lubricatedsliding mount is combined here with a pretensioned sliding mountcorresponding to a meaningful embodiment of the present invention.Accordingly, it is meaningful to place the sliding layer on the innerpart under pretension. As a result, the noise generation can be reducedor eliminated altogether, on the one hand, and clearance of the joint,which affects the parameters of the mount, can be prevented.Consequently, a friction-optimized sliding mount can be obtained withsuch a measure.

To guarantee the grease lubrication of a sleeve joint according to thepresent invention during the entire service life of the sleeve joint, itis, moreover, proposed that the sliding layer be provided with greasepockets filled with grease on its contact surface with the inner part.The grease can be prevented from escaping from the grease pockets in asimple manner by the sliding layer having a labyrinth seal on the samecontact surface, the labyrinth seal being provided preferably but notobligatorily in the outer edge areas of the sliding layer. As a result,grease is thus effectively prevented from escaping even during movementsof the parts of the sliding mount relative to one another for the axialmovement of the mount assembly unit. The service life of such a sleevejoint according to the present invention can be decisively improved.

Moreover, it is proposed in the course of the simplification of themanufacture of the sleeve joint that the inner part be designed as adrawn, tubular component made preferably of aluminum. Aluminum isespecially suitable because, on the one hand, it is an ideal frictionpartner and, on the other hand, it does not require any additionalsurface protection. Moreover, aluminum also offers considerableadvantages in terms of weight compared with other materials.

According to another embodiment of the present invention, the inner partis preferably placed on the component to be mounted by means of a pressfit. In order not to affect the sliding mount by this connection morethan absolutely necessary, care should be taken to ensure that the pressfit is provided in the area of the contacts between the edge areas ofthe sealing bellows and the inner part.

As was mentioned above, a stabilizer bar of a motor vehicle may be usedas a component to be mounted. The press fit between the inner part andthe component (stabilizer bar) to be mounted has the decisive advantagethat no additional mounting steps are necessary to fix the sleeve jointaccording to the present invention in its specified position on thecomponent to be mounted. Thus, the mounting is considerably simplified.

According to a highly advantageous variant of the present invention, thesleeve joint can be fastened directly to the lower suspension arm of amotor vehicle by means of a flanged bearing or by means of strapspresent on the housing. Such a mounting of the sleeve joint makespossible a wheel suspension without the hitherto necessary rockerpendulums. These components can be eliminated altogether, so that notonly is a sleeve joint according to the present invention characterizedby its advantageous, more economical manufacturability, but, moreover,the entire wheel suspension of a motor vehicle can be considerablysimplified and hence improved.

With the sleeve joint presented here according to the invention beingdescribed here, a sleeve joint was created for the first time that hasan additional axial sliding mount. It is designed as a closed sleevejoint with grease lubrication and thus it has an axial displacingfunction. The wear characteristic was able to be considerably improved.In addition, disturbing squeaky noises can be avoided in the area of thewheel suspension of the motor vehicle. Due to the compact design of awheel-side stabilizer mount, which does not introduce bending forcesinto the stabilizer on the frame side in case of a correspondinglydesigned mount, an overall improvement is thus achieved in the responsecharacteristic of the stabilizer in a motor vehicle. The stabilizermount may be positioned very far out at the suspension arm on the wheelside. As a result, the response characteristic of the stabilizer islikewise improved, and the wheel suspension is qualitatively optimized.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this disclosure. For a better understanding of the invention,its operating advantages and specific objects attained by its uses,reference is made to the accompanying drawings and descriptive matter inwhich a preferred embodiment of the invention is illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a detail of a sleeve joint according tothe present invention, and

FIG. 2 is a detail of a part of a wheel suspension of a motor vehiclewith a sleeve joint according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings in particular, FIG. 1 shows a detail of asectional view through a preferred exemplary embodiment of a sleevejoint according to the present invention. This sleeve joint comprises amount assembly unit designated by 1 as a whole, which is connected to aninner part 2 via a sliding mount in an axially displaceable manner. Themount assembly unit 1 comprises in turn a housing 3, into which abearing shell 4 made of a plastic is inserted. On its inner side facingaway from the inner surface of the housing, the bearing shell 4 has acurved support surface having a shape complementary to the mount body 6.The mount body 6 consequently has a curved support surface 5 which isslidingly movable in the bearing shell 4. On its inner surface 7 facingaway from the bearing shell 4, the mount body 6 has a sliding layer 8.This sliding layer 8 is directly in sliding contact with the inner part2 under pretension. To improve the coefficients of friction, greasepockets 20, which act as grease reservoirs and into which lubricatinggrease is introduced, are formed on the sliding layer 8. The inner part2 is placed on the component to be mounted, which is designed as astabilizer bar 19 by means of a press fit. To protect the sensitiveinner components of the sleeve joint according to the present inventionagainst the penetration of contaminants or corrosive media, the sleevejoint shown in FIG. 1 has a sealing bellows 9 and 10 each on each of itsaxially outer sides. The sealing bellows 9, 10 have a first edge area 11and 12, respectively, as well as a second edge area 14 and 15,respectively. The first edge area 11, 12 of the sealing bellows 9, 10 isinserted into a housing mount 13. FIG. 1 shows two differentpossibilities of fastening this first edge area of the sealing bellows.In the upper part of the figure, the first edge area 11 of the sealingbellows 9 is mounted within a groove 21 in the housing 3. It is pressedinto this groove 21 by means of a straining ring 17. In the lower partof FIG. 1, the edge area 12 of the sealing bellows 10 is inserted into aclosing ring 18 and is held within this closing ring 18 by means of astraining ring 17. The closing ring 18 is in turn nondetachablyconnected to the housing 3 by a deformed rolled edge of the housing 3.It is used at the same time as an axial securing means for the bearingshell 4 within the housing 3. A straining ring 16, which fixes the edgeareas 14 and 15 of the sealing bellows, is used to fix the second edgeareas 14 and 15 of the respective sealing bellows 9 and 10 on the innerpart 2 and thus to achieve the sealing of the sleeve joint.

FIG. 2 shows a detail of part of a wheel suspension of a motor vehiclewith a sleeve joint according to the present invention. The sleevejoint, comprising the mount assembly unit 1, which is placed on theinner part 2 slidingly movably in the longitudinal direction of thesleeve joint, is fastened by means of a flange 22 on a suspension arm 23of a motor vehicle wheel suspension in the view shown in FIG. 2. A screwconnection, which is only indicated by crosses at the flange 22 in thedrawing, is used for the mounting. The flange 22 is made in one piecewith the housing 3 of the sleeve joint in the embodiment being shown,i.e., it is made in one piece with the housing. The suspension arm 23 isconnected to a wheel carrier or steering knuckle 24 of the wheelsuspension by means of a ball-and-socket joint 25 designed as a supportjoint. Rocker pendulums may be eliminated due to the use of a sleevejoint according to the present invention in a wheel suspension.

What a specific embodiment of the invention has been shown and describedin detail to illustrate the application of the principles of theinvention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

1. A sleeve joint comprising: a mount assembly unit; and an inner part,wherein said mount assembly unit has a housing as well as a mount bodyand a bearing shell inserted into said housing for the slidingly movablemounting of said mount body provided with a curved support surface, andsaid mount body is provided with a sliding layer on an inner surfacefacing away from said curved support surface, so that sliding movementof said mount assembly unit in the longitudinal direction of the sleevejoint is made possible as a consequence of the sliding contact betweensaid mount assembly unit and said inner part associated therewith, saidsliding layer being placed on said inner part under pretension.
 2. Asleeve joint in accordance with claim 1, wherein said sleeve joint,which is sealed by a seal to the outside, has a grease lubrication forsaid slidingly movable mount parts.
 3. A sleeve joint in accordance withclaim 1, wherein said sliding layer consists of a low-fiction plastic ora synthetic rubber.
 4. A sleeve joint in accordance with claim 3,wherein the material of said sliding layer can be injection molded.
 5. Asleeve joint in accordance with claim 1, wherein said sliding layer isinserted into said mount body by means of a press fit.
 6. A sleeve jointin accordance with claim 1, wherein said sliding layer has grease-filledgrease pockets on its contact surface with said inner part.
 7. A sleevejoint in accordance with claim 1, wherein on its contact surface withsaid inner part, said sliding layer has a labyrinth seal, which isarranged at the outer edge areas of said sliding layer.
 8. A sleevejoint in accordance with claim 1, wherein said inner part is a drawn,tubular component.
 9. A sleeve joint in accordance with claim 8, whereinsaid drawn, tubular component is made of aluminum.
 10. A sleeve jointarrangement comprising: a mount assembly unit with a housing, a mountbody with a curved support surface and with a sliding layer facing awayfrom said curved support surface and a bearing shell inserted into saidhousing for the slidingly movable mounting of said mount body along saidcurved support surface; an inner part, sliding contact between saidmount assembly unit sliding layer and said inner part allowing slidingmovement of said mount assembly unit in a longitudinal direction of thesleeve joint arrangement; a component, said inner part being press fiton said component.
 11. A sleeve joint arrangement in accordance withclaim 10, further comprising: a housing mount and a sleeve joint sealfor sealing to the outside, said seal having grease lubrication forslidingly movable mount parts, wherein said seal of the sleeve jointcomprises two sealing bellows having a first edge area inserted intosaid housing mount and having a second edge area brought sealingly intocontact with said inner part.
 12. A sleeve joint comprising: a mountassembly unit; an inner part, wherein said mount assembly unit has ahousing as well as a mount body and a bearing shell inserted into saidhousing for the slidingly movable mounting of said mount body providedwith a curved support surface, and said mount body is provided with asliding layer on an inner surface facing away from said curved supportsurface, so that sliding movement of said mount assembly unit in thelongitudinal direction of the sleeve joint is made possible as aconsequence of the sliding contact between said mount assembly unit andsaid inner part associated therewith; a housing mount, and wherein saidseal of the sleeve joint comprises two sealing bellows having a firstedge area inserted into said housing mount and having a second edge areabrought sealingly into contact with said inner part.
 13. A sleeve jointin accordance with claim 12, wherein said housing mount is a groove inan outer surface of said housing or a closing ring, which is connectedwith said housing and receives said edge area (11, 12) of said sealingbellows.
 14. A sleeve joint in accordance with claim 12, wherein saidsealing bellows are fixed on said associated components by saidstraining rings.
 15. A sleeve joint comprising: a mount assembly unit;an inner part, wherein said mount assembly unit has a housing as well asa mount body and a bearing shell inserted into said housing for theslidingly movable mounting of said mount body provided with a curvedsupport surface, and said mount body is provided with a sliding layer onan inner surface facing away from said curved support surface, so thatsliding movement of said mount assembly unit in the longitudinaldirection of the sleeve joint is made possible as a consequence of thesliding contact between said mount assembly unit and said inner partassociated therewith, said sleeve joint being placed on a stabilizer barof a motor vehicle.
 16. A sleeve joint in accordance with claim 15,wherein the connection between said stabilizer bar and said inner partof said sleeve joint is a press fit.
 17. A sleeve joint comprising: amount assembly unit with a housing, a mount body with a curved supportsurface and with a sliding layer facing away from said curved supportsurface and a bearing shelf inserted into said housing fur the slidinglymovable mounting of said mount body along said curved support surface;an inner part, sliding contact between said mount assembly unit slidinglayer and said inner part allowing sliding movement of said mountassembly unit in a longitudinal direction of the sleeve joint; a housingmount and a sleeve joint seal for sealing to the outside, said sealhaving grease lubrication fur slidingly movable mount parts, whereinsaid seal of the sleeve joint comprises two sealing bellows having afirst edge area inserted into said housing mount and having a secondedge area brought sealingly into contact with said inner part.
 18. Asleeve joint comprising: a mount assembly unit; an inner part, whereinsaid mount assembly unit has a housing as well as a mount body and abearing shell inserted into said housing for the slidingly movablemounting of said mount body provided with a curved support surface, andsaid mount body is provided with a sliding layer on an inner surfacefacing away from said curved support surface, so that sliding movementof said mount assembly unit in the longitudinal direction of the sleevejoint is made possible as a consequence of the sliding contact betweensaid mount assembly unit and said inner part associated therewith, saidsliding layer has a labyrinth seal on its contact surface with saidinner part which is arranged at the outer edge areas of said slidinglayer.
 19. A sleeve joint comprising: a mount assembly unit; an innerpart, wherein said mount assembly unit has a housing as well as a mountbody and a bearing shell inserted into said housing for the slidinglymovable mounting of said mount body provided with a curved supportsurface, and said mount body is provided with a sliding layer on aninner surface facing away from said curved support surface, so thatsliding movement of said mount assembly unit an the longitudinaldirection of the sleeve joint is made possible as a consequence of thesliding contact between said mount assembly unit and said inner partassociated therewith, said sleeve joint being fastened directly to thelower suspension arm of a motor vehicle by means of a flanged bearing orby means of at least one strap present on said housing or by means of aflange.